Hotrod your Hermes


I've owned the new 24/192 Kora Hermes for several months now. Right after I got it, I commented on one of the threads about the excellent performance of this DAC, especially at it's price point. I promised to provide a more thorough review of this DAC after it had some time on it. Unfortunately, I failed to do this. Reason being, I began modifications on this unit after observing the open architecture inside it. Since then, I have done the following:
1. Replaced the stock tubes with Seimans gold pins (Be careful doing this. The current Hermes has pin type tube sockets with springs inside them. Lose a spring, and your tube won't make contact. No warnings in the manual about this. This happened to me. Luckily, JC Audio exchanged my "missing springs" DAC for a brand new one. Great customer service!! In the future, Kora plans to change these sockets)
2. Top Hat tube dampers
3. Audio Magic 99.999 silver wire on all inputs and outputs
4. Shakti on-lines on the circuit board
5. Shielded the two transformers from each other and the circuit board using non-magnetic MU metal
6. Replaced all caps with a mixture of MIT, Hovland, and high precision oil caps
7. Shakti stone on the transformers
8. Replaced input and output jacks with WBTs
This turned this already excellent DAC into....A MONSTER!! Why? There is only one way to describe the performance of the Hotrod Hermes. IT'S ALIVE!!! The silence of the background is stunning. The images are more palpable and more full bodied. The soundstage is deeper and wider. The background is blacker, and details you never believed were on redbook CDs are now clearly audible. Yet this DAC remains extremely musical. This is by far and away the best DAC I've heard. Not an analytical bone in it's body. A friend of mine also modified his this way, and will add to this thread about his impressions. Jerry Ramsey of Audio Magic suggested many of these mods, and did the serious ones. He does excellent work if you need someone to do it for you. If you own a Hermes, you must consider doing all or some of these things. The potential to make an already excellent DAC into a world beater is huge with this thing. And the cost of the DAC and mods keeps you under $2500.
glreno

Showing 9 responses by glreno

Hi John! I don't think Jerry could add the toslink. The last DACs I owned were the Altis Reference and Audiomeca Enkianthus. The Kora was as good or better than either WITHOUT the mods. My friend who also had his modified the same way had the DCS Delius and the Audiomeca Enkianthus. He also thought the stock Kora was better than his previous DACs. The comparison between the Enkianthus and your Audio Aero should be significant, since they both use 24/192 DACs with the Anagram Technologies resampler.
Hi Tk4qmmt! If you're not comfortable doing the mods yourself, don't. I'm with you. I had Jerry do the caps and the wire. He also has the MU metal for the shielding. The other stuff is easy, as long as you are careful removing the tubes. He does a terric job, and it works when he's done. Even at $3000., it's a screaming deal for the sound quality. You can call him at 303-369-1814.
You would probably get better redbook playback using the non-SACD separates. Depends on your priorities and CD collection. I won't consider SACD for two reasons at the moment...very limited software and my huge redbook CD collection.
Jerry's e-mail address is info@audio-magic.com. That's cool that Kora has decided to do these things at the factory. Is Kora going to do all of the caps (5 total), or just some? Also, is this something they are doing now? There is one other thing I am going to try. I am going to mount the transformers on Vibrapods. The transformers are mounted on the base of the unit. The circuit board is elevated, but bolted to the base. I have had very good results using Combak/Harmonix tuning devices on other circuit boards to control vibration. My first thought when I saw this was that the transformers would send vibration to the board via the chassis. It looks like Kora has addressed this somewhat by a thin rubber pad under each transformer. How about a more effective vibration control using Vibrapods, and eliminate vibration from the transformers before it gets to the boards? The transformers are torodials,and held in place by one bolt through the center. The Vibrapods already have a hole through the center, and it's the same size as the bolt. The Vibrapods can be affected by high heat, but the transformers are only warm to the touch. And they are cheap. Worth a try, anyway.
Hey Joe! I noted that you were, at one time, putting different cones on these things. Since this is a metric thread, were you tapping out the existing nut with english 1/4 inch threads?
I finished with the last modification I intend to do with the Hermes, that being isolating the toroidal transformers from the chassis. I should note that many of these modifications were done incrimentally so I could hear what was taking place after each one. I disagree with the Kora designers. Shielding the transformers and DAC with MU metal made an obvious difference. It was done at the same time the boards received vibration damping. The result was a blacker background and more perceived detail. The biggest surprise came when I put vibrapods under the transformers. Layering within the soundstage became more defined, and inner detail improved significantly. Instruments and vocals also became more full bodied. This was not subtle. Use vibrapod #5s, so you can put some torque on the nuts holding the transformers without collapsing the vibrapods and making them ineffective. I also experimented with Black Diamond cones under the DAC. They also helped, but I have many different kinds of cones that all seemed to tighten images within the soundstage. Just about all of them work better than what's on there. Happy tweaking!!
Okay, just one more tweak, BLUE LEDs!!! God Joe, do something to get Kora to change those ugly, butterscotch yellow LEDs. Jerry at Audio Magic changed mine to blue and they are WAY COOL!!! And they sound so much better than the blue ones:).